Stator winding and manufacturing method therefor

Abstract

A stator winding which copes with high output and miniaturization turns formed by winding a wire sheaf of a plurality of fine wires bundled together, in an approximately rhombic shape, wherein the turns are arranged so as to be sequentially shifted in the direction of one diagonal of the rhombic shape, to thereby form an approximately rhombic shape coil segment comprising a continuous length of the wire sheaf. A plurality of coil segments are then sequentially shifted and overlapped on one diagonal to form a band shaped body, and a hollow cylindrical body is then formed by rolling the band shaped body into a circular shape. The winding is characterized in that with each turn, opposite end portions located in the direction of an other diagonal orthogonal to the direction of the one diagonal have U-shape bent back portions.

What is claimed is:  
     
       1. A stator winding for use in a rotating electric machine having a slotless stator, said stator winding being a hollow cylindrical body formed by: 
       forming turns by winding a wire sheaf of a plurality of fine wires composed of conductors bundled together, though one turn in an approximately rhombic shape;  
       forming approximately rhombic shaped coil segments comprising a continuous length of said wire sheaf by winding and arranging a plurality of said turns so as to be sequentially shifted continuously in a direction of one diagonal of said rhombic shape;  
       forming a band shape body using a plurality of said coil segments with these coil segments sequentially shifted in the direction of said one diagonal and so as to be adjacent to each other; and  
       rolling said band shaped body into a hollow cylindrical shape;  
       wherein with each of said respective turns, opposite end portions which are located in a direction of another diagonal of said rhombic shape orthogonal to the direction of said one diagonal, have bent back portions which are disposed outside of said rhombic shape;  
       said bent back portions become end portions of said hollow cylindrical body; and  
       said bent back portions are bent to an inner peripheral side of said hollow cylindrical body.  
     
     
       2. A stator winding according to  claim 1 , wherein with said wire sheaf, one end portion of said opposite end portions of said respective turns which are located in said direction of another diagonal of said rhombic shape orthogonal to the direction of said one diagonal is wound from the inner peripheral side of said hollow cylindrical body to an outer peripheral side thereof, and another and portion of said opposite end portions of said respective turns, is wound from the outer peripheral side of said hollow cylindrical body to the inner peripheral side thereof. 
     
     
       3. A stator winding according to  claim 2 , wherein said bent back portions proceed so as to project outside of said turn, and then return back in an approximately U-shape and proceed so as to return inside of side turn. 
     
     
       4. A stator winding according to  claim 2 , wherein of the four sides of said approximately rhombic shaped coil segments, two said sides located on one side of said other diagonal of said rhombic shape are arranged on the inner peripheral side of said hollow cylindrical body, and the other two said sides opposite to the two said sides located on said one side are arranged on an outer peripheral side of said hollow cylindrical body. 
     
     
       5. A stator winding according to  claim 4 , wherein the two sides of the coil segment which are arranged on the inner peripheral side of said hollow cylindrical body are abutted in the circumferential direction against said two sides which are arranged on the inner peripheral side of the coil segment adjacent thereto. 
     
     
       6. A stator winding according to  claim 1 , wherein said bent back portions proceed so as to project outside of said turn, then return back in an approximately U-shaped and proceed so as to return inside of said turn. 
     
     
       7. A stator winding according to  claim 6 , wherein said bent back portions are bent from the outer peripheral side of said hollow cylindrical body towards the inner peripheral side thereof. 
     
     
       8. A stator winding according to  claim 6 , wherein of the four sides of said approximately rhombic shaped coil segments, two said sides located on one side of said other diagonal of said rhombic shape are arranged on the inner peripheral side of mid hollow cylindrical body, and the other two said sides opposite to the two said sides located on said one side are arranged on an outer peripheral side of said hollow cylindrical body. 
     
     
       9. A stator winding according to  claim 1 , wherein said wire sheaf has an approximately rectangular shaped cross-section. 
     
     
       10. A stator winding according to  claim 1 , wherein said fine wires have a distorted circular cross-section with linear portions, and adjacent fine wires are contacted together at said linear portions. 
     
     
       11. A stator winding according to  claim 1 , wherein said respective turns are arranged touching adjacent ones of said turns. 
     
     
       12. A stator winding according to  claim 1 , wherein outer peripheral sides of the sequentially adjacent coil segments radially overlap inner peripheral sides of the adjacent coil segments in the hollow cylindrical shape. 
     
     
       13. A stator winding according to  claim 1 , wherein each said coil segment is sequentially shifted such that portions of multiple turns of said coil overlap with portions of multiple turns an adjacent one of said coil segments. 
     
     
       14. A stator winding according to  claim 1 , wherein each said turn is wound in the same manner. 
     
     
       15. A stator winding for use in a rotating electric machine having a slotless stator, said stator winding being a hollow cylindrical body formed by: 
       forming turns by winding a wire sheaf of a plurality of fine wires composed of conductors bundled together, though one turn in an approximately rhombic shape;  
       forming approximately rhombic shaped coil segments comprising a continuous length of said wire sheaf by winding and arranging a plurality of said turns so as to be sequentially shifted continuously in a direction of one diagonal of said rhombic shape;  
       forming a band shaped body using a plurality of said coil segments with these coil segments sequentially shifted in the direction of said one diagonal and so as to be adjacent to each other; and  
       rolling said band shaped body into a hollow cylindrical shape;  
       wherein said wire sheaf is twisted at least one turn in a helical form within a range of one side of the respective approximate rhombic shaped turns.  
     
     
       16. A stator winding for use in a rotating electric machine having a slotless stator, comprising a band shaped body of a plurality of coil segments rolled into a hollow cylindrical shape, wherein: 
       each of said coil segments is approximately rhombic shaped and includes a continuous length of a wire sheaf wound and arranged into a plurality of turns which are sequentially shifted continuously in a direction of one diagonal of said rhombic shape;  
       each of said turns is also approximately rhombic shaped;  
       said wire sheaf includes a plurality of fine wires composed of conductors bundled together;  
       said plurality of said coil segments of said band shaped body are sequentially shifted in the direction of said one diagonal and so as to be adjacent to each other; and  
       with each of said respective turns, opposite end portions which are located in a direction of another diagonal of said rhombic shape orthogonal to the direction of said one diagonal, have bent back portions which are disposed outside of said rhombic shape;  
       said bent back potions become end portions of said hollow cylindrical body; and  
       said bent back portions are bent to an inner peripheral side of said hollow cylindrical body.  
     
     
       17. A stator winding according to  claim 16 , wherein with said wire sheaf, one end portion of said opposite end portions of respective ones of said turns which are located in said direction of another diagonal of said rhombic shape orthogonal to the direction of said one diagonal is wound from the inner peripheral side of said hollow cylindrical body to an outer peripheral side thereof, and another end portion of said opposite end portions of said respective turns, is wound from the outer peripheral side of said hollow cylindrical body to the inner peripheral side thereof. 
     
     
       18. A stator winding according to  claim 16 , wherein said bent back portions proceed so as to project outside of said turn, and then return back in an approximately U-shape and proceed so as to return inside of said turn. 
     
     
       19. A stator winding according to  claim 16 , wherein outer peripheral sides of the sequentially adjacent coil segments radially overlap inner peripheral sides of the adjacent coil segments in the hollow cylindrical shape.